SPRINGFIELD, Ill. — Illinois lawmakers are in line for a $1,600-a-year salary increase after the House surprised the Senate by slipping a pay raise into budget legislation, then refusing to take action on the Senate’s attempt to reverse it.

The $39.9 billion budget the House adopted Saturday night, followed Sunday by Senate action which ended the Legislature’s spring session, includes a 2.4% cost-of-living adjustment in legislators’ base salary of $67,836.

It would be the first pay increase for lawmakers since 2008 and would take effect July 1, if Democratic Gov. J.B. Pritzker signs the budget agreement, which all 19 Senate Republicans opposed because of the pay raise.

“If we think we deserve one, then stand up and say it,” said Sen. Dale Righter, a Mattoon Republican who was the first to point out the missing COLA freeze to majority Democrats. “Don’t try to slip it through in the last hours of session because that’s what people resent.”

Lawmakers are due annual cost-of-living increases unless legislation blocks them. For a decade, budget legislation has included language to freeze salaries.

During Friday night’s budget debate, sponsoring Democratic Sen. Heather Steans was surprised when Righter pointed out that the agreed-to COLA freeze was absent. Senate Democrats reversed the omission by adding the prohibition to another bill they sent to the House, but the House took no action.

“You should go and ask the House why they didn’t pass the bill that we sent them,” Steans said.

Pritzker, at a celebratory end-of-session news conference in his state Capitol office, declined to say whether lawmakers who believe they deserve a pay raise should do so in a more open fashion.

“This is the budget that we’ve got,” Pritzker said.

House Majority Leader Greg Harris, a Chicago Democrat, would not say why the House didn’t vote on the separate salary-freeze legislation, noting only that the budget plan including the COLA underwent committee and House-floor examination.

A spokesman for Democratic House Speaker Michael Madigan said he was unaware of a pay increase. But Rep. David McSweeney, a Republican budget hawk from Barrington Hills, was incensed.

“Illinois citizens are sick and tired of secret insider budget deals that enrich Springfield politicians at the expense of hardworking taxpayers who are getting hit with massive tax increases,” McSweeney said.

The salary freeze plan that the Senate sent to the House would have required a roll call of House members on whether to implement the freeze or accept the raise.

“They were aware that we passed the bill over to them, so for whatever reason, I don’t know what happened over there, they didn’t take it up,” said Senate President John Cullerton, a Democrat from Chicago. “But I would advise them to do so.”

The Senate added the freeze language to unrelated legislation sponsored by Democratic Rep. Stephanie Kifowit. When it came back to the House, records indicate Kifowit transferred it to Democratic Rep. Thaddeus Jones of Calumet City. Jones filed a motion to reject the freeze, but it was never called for a vote. Neither Jones nor Kifowit returned messages seeking comment on Sunday.

It’s unclear when House Republicans learned that the COLA was included, but legislative records show that on Saturday, the entire GOP caucus signed on as co-sponsors to Metropolis Republican Rep. Patrick Windhorst’s bill prohibiting lawmakers from acceptingCOLAs or increased reimbursement for mileage, lodging or meals in the 2020 fiscal year.

Assistant Republican Leader Avery Bourne of Raymond called it “responsible.”

“With our state facing so many financial challenges,” said Bourne, “we should not be raising lawmakers’ pay.”